1. Field of the Invention
The present invention relates to a method for monitoring an engine system for a motor vehicle such that unintentional accelerations of the motor vehicle are prevented.
2. Description of the Related Art
The operation of engine systems in motor vehicles is a safety-critical function, which is why measures for monitoring for proper functioning are serially provided. In monitoring, it is customary in particular to use three-level concepts, in which control unit functions are monitored by a torque-based or acceleration-based monitoring function. This should prevent unintentional accelerations of a motor vehicle, such as that which might occur due to a software or hardware bug in the engine control unit, for example.
Monitoring generally triggers a fault response when the ascertained engine torque or the ascertained acceleration of the vehicle is implausible and/or a predefined maximum allowed value of the monitored variable is exceeded. These methods permit a sufficiently rapid response to faults occurring in the normal driving condition.
For tolerance reasons, previous methods for detecting unintentional accelerations have used threshold values and detection times, which are suitable for driving conditions at higher speeds but do not ensure a sufficiently rapid response in the event of a fault in the speed range approaching a standstill. In particular, monitoring methods today take too much time to prevent an approach to a pedestrian who is crossing the road directly in front of the motor vehicle, for example.